With the small button on the top of the alarm you can turn on the light. When the chain is pulled from the alarm at the top, the pin disconnects from the device and a piercing alarm sound goes off. This is how you can confuse your attacker and draw attention to you. If you want to turn off the alarm, you have to plug the pen back in.

Alternatively, you can quickly press the alarm button twice, then the alarm goes off with 130 decibels and the light flickers. You can turn it off by staying pressed on the alarm button for about 3 seconds.

This keychain alarm can be recharged via USB with the included cable.